Certified Rhythm Analysis Technician (CRAT) Practice Exam

To determine the atrial rate based on the described ECG caliper measurement, it's essential to understand the relationship between the number of small boxes and the heart rate. In this scenario, five small boxes were measured between two peak-to-peak flutter waves.

In an ECG, the standard method to calculate the heart rate is by recognizing that each small box on the ECG paper represents 0.04 seconds. The total duration between the two flutter waves can thus be calculated. Since there are five small boxes, this equates to 0.04 seconds per box multiplied by five, resulting in a total of 0.2 seconds for one complete cycle of flutter waves.

To find the atrial rate, you can use the formula:

\[ \text{Heart Rate (bpm)} = \frac{60}{\text{Time (in minutes)}} \]

Given that 0.2 seconds is equal to \(\frac{0.2}{60}\) minutes, the calculation for the rate becomes:

\[ \text{Atrial Rate} = \frac{60}{\frac{0.2}{60}} = \frac{60 \times 60}{0.2} = 300 \text{ bpm} \]

Thus